How does Bruch's membrane appear in an OCT scan?

How does Bruch's membrane appear in an OCT scan?

• A. A thick elevated ridge at the vitreous boundary
• B. A dark band anterior to the RPE
• C. A thin, highly reflective line just posterior to the RPE
• D. A bright circular ring at the optic nerve

Answer: (C)

The key idea is how OCT shows retinal boundaries by reflectivity. Bruch's membrane sits between the RPE and the choroid, and on OCT it appears as a very thin, highly reflective line just posterior to the RPE. The bright line marks the boundary between the RPE and the choroid, so you’ll see a distinct, slim reflective line immediately behind the RPE. Other options describe structures not Bruch's membrane: a thick elevated ridge at the vitreous boundary would relate to the vitreoretinal interface, a dark band in front of the RPE isn’t the Bruch’s membrane line, and a bright circular ring at the optic nerve relates to the optic nerve head region, not Bruch's membrane.

The key idea is how OCT shows retinal boundaries by reflectivity. Bruch's membrane sits between the RPE and the choroid, and on OCT it appears as a very thin, highly reflective line just posterior to the RPE. The bright line marks the boundary between the RPE and the choroid, so you’ll see a distinct, slim reflective line immediately behind the RPE.

Other options describe structures not Bruch's membrane: a thick elevated ridge at the vitreous boundary would relate to the vitreoretinal interface, a dark band in front of the RPE isn’t the Bruch’s membrane line, and a bright circular ring at the optic nerve relates to the optic nerve head region, not Bruch's membrane.